Nano Archive

Metallic LiMo3Se3 nanowire film sensors for electrical detection of metal ions in water

Allen, Mark and Sabio, Erwin M. and Qi, Xiubin and Nwengela, Bokuba and Islam, M. Saif and Osterloh, Frank E. (2008) Metallic LiMo3Se3 nanowire film sensors for electrical detection of metal ions in water. LANGMUIR, 24 (13). pp. 7031-7037.

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Official URL: http://dx.doi.org/10.1021/la8004085

Abstract

LiMo3Se3 nanowire film sensors were fabricated by drop-coating a 0.05% (mass) aqueous nanowire solution onto microfabricated indium tin oxide electrode pairs. According to scanning electron microscopy (SEM) and atomic force microscopy (AFM), the films are made of a dense network of 3−7 nm thick nanowire bundles. Immersion of the films in 1.0 M aqueous solutions of group 1 or 2 element halides or of Zn(II), Mn(II), Fe(II), or Co(II) chlorides results in an increase of the electrical resistance of the films. The resistance change is always positive and reaches up to 9% of the base resistance of the films. It occurs over the course of 30−240 s, and it is reversible for monovalent ions and partially reversible for divalent ions. The signal depends on the concentration of the electrolyte and on the size and charge of the metal cation. Anions do not play a significant role, presumably, because they are repelled by the negatively charged nanowire strands. The magnitude of the electrical response and its sign suggest that it is due to analyte-induced scattering of conduction electrons in the nanowires. An ion-induced field effect can be excluded based on gated conductance measurements of the nanowire films.

Item Type:Article
Subjects:Physical Science > Nanophysics
Material Science > Nanofabrication processes and tools
Material Science > Nanostructured materials
Material Science > Nanochemistry
ID Code:1225
Deposited By:Anuj Seth
Deposited On:16 Dec 2008 10:56
Last Modified:19 Jan 2009 11:36

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